OBJECTIVE: To develop and evaluate granulocyte transfusion therapy as a life-support procedure in the treatment of idiopathic and iatrogenic agranulocytosis. APPROACH: Methods of granulocyte procurement from normal donors will be compared for donor safety and harvesting efficiency. The value of granulocyte transfusions in the treatment of existing bacterial injection in agranulocytic patients will be assessed. A prospectively randomized study of the value of granulocyte transfusions in prophylaxis against bacterial infection of agranulocytic patients is being made. Uninfected patients are randomized to transfused and non-transfused groups. These studies are being undertaken in patients receiving allogeneic marrow transplants as part of the treatment of leukemia or marrow aplasia.